While the gecko, known for its ability to climb vertical surfaces, has had a couple of hundred million years to engineer its adhesive, Northen and Turner have been at it for less than two years. To play catch up they use some very powerful tools. Working alongside researchers producing cutting edge light emitting diodes (LEDs) and the latest in chip-scale lasers, Northen uses the UCSB nanofabrication facilities in quite a different manner. Instead of creating transistors to manipulate electrons at the sub-micrometre scale, like in your computer, he creates micro- and nano-structures to enhance short-range surface forces.
The system, explained in more detail in the August edition of Nanotechnology, consists of micro-scale flexible platforms coated with vertically aligned polymeric nanorods. While the micro-scale platforms proved a minor challenge to produce, coating them with nanorods presented Northen with a bit more of a hurdle. “I was trying everything I could possibly imagine to create polymer nanorods on top of those flexible platforms, but then [on one of my samples] I noticed it happening all on its own,” he said. “I was so excited. Then the real challenge came in figuring out what was going on and how to reproduce it.”
And what’s on the horizon for this work? First is the optimization of the structures to maximize adhesion. Then the challenge will be to switch the adhesion off, or as Northen puts it: “It’s kind of like four-wheeling, the real trick isn’t getting stuck, but getting unstuck!”